Rangers Abe Philipson, left, and John DeWolfe of the Florida Division of Forestry watch fire sweep through pine flatwoods Tuesday in the Mobbly Bayou Wilderness Preserve in Oldsmar. Four acres of the park’s preserve burned Monday.

Barely halfway through the year, wildfires in Florida have burned more than twice the acreage of all of 2010, and wind is pushing smoke from several blazes in Central Florida toward Tampa Bay.

On Tuesday, 266 fires were active in Florida, according to the Florida Division of Forestry. The dry months of March, April and May are the busiest for wildfires, said Cliff Frazier, a spokesman for the agency's Orlando district, but the potential for huge fires will continue as long as the weather stays dry.

Although Tampa Bay has had substantial rain this year — more than twice the average amount in the first three months — a dry May has increased wildfire risk.

The National Weather Service says Pinellas, Pasco and Hernando counties are at very high risk of fire. In Hillsborough County, the fire risk is considered high.

"It's pretty bad right now," Frazier said. "A small wildfire can spread in a matter of minutes with the wind."

A combination of high winds, low humidity, little rainfall and dead vegetation left over from several winter freezes creates perfect conditions for wildfires, Frazier said. The risk is also great for big fires, like one in March that started as a 10-acre fire and eventually burned 17,000 acres across Brevard and Volusia counties.

There were no major fires burning Tuesday in Pinellas, Hillsborough and Polk counties, though a brush fire broke out in Oldsmar, but all the counties already have seen significantly more wildfire activity this year.

In Osceola County, south of Orlando, a fire that started Friday consumed 1,520 acres by Tuesday. In all of 2010, in comparison, the county saw 1,319 acres burn. Fire rangers from North Florida were sent to relieve local officials.

"They've been going at it nonstop," Frazier said.

As winds push smoke toward Tampa Bay, the smell will be most noticeable in the morning and evening, said Diane Kacmarik, a Bay News 9 meteorologist.

Tampa had 0.70 inches of rain in May, below the average of 2.85. St. Petersburg had 2.07 inches, below the average of 2.80.

Areas of Central Florida were also reporting drought indexes above 500, which is considered high. In the area of Pinellas, Hillsborough and Polk counties, it's 551, said Kristen Bennett, a duty officer for the Florida Division of Forestry in the Lakeland district.

Officials urge the public to be careful with outdoor cooking or campfires, officials said. Debris should be cleaned off roofs, and plants and trees in yards shouldn't be too close to a house. If roads are smoky, drivers should treat it as fog and drive slowly with the low beams turned on.

Times staff writer Danny Valentine contributed to this report. Ileana Morales can be reached at imorales@sptimes.com or (813)226-3386.